Rubber parts contacting with fuel oil have been made of selected rubber materials whose durability is not impaired by contact with fuel oil. For example, fuel oil hoses have conventionally been produced from oil-resistant rubbers, such as a nitrile rubber (NBR) and a hydrin rubber, e.g., an epichlorohydrin polymer (CO) and an ethylene oxide-epichlorohydrin copolymer (ECO). However, alcohol-added gasoline (hereinafter referred to as "gasohol") has recently appeared on the market due to a combination of circumstances, and deterioration of rubber parts due to contact with gasohol, in particular the volume change on immersion in gasohol, becomes a serious problem. Therefore, NBR, CO, ECO, etc., do not always exhibit sufficient resistance to gasoline for use as a fuel oil hose material, and it has been keenly demanded to develop a rubber material having further improved durability.